Rotatable rocket having means for preventing flameout due to centrifugal force created during rotation thereof

ABSTRACT

A rocket device comprising an elongated generally tubular shaped housing; a propulsion charge in one end of the housing; means for directing the products of combustion of the propulsion charge rearwardly of the housing in a manner so as to impart rotary motion to the device as it is propelled forwardly by the charge; signal means in the form of a quantity of radar signaling chaff in the housing; an expulsion charge for expelling the signaling means from the housing; means including a combustable material within the housing for igniting the expulsion charge at a predetermined time after the propulsion charge has been ignited, and an enclosure for operatively supporting the combustable material within the housing and for preventing the ignited portion of the combustable material from being forced out of the enclosure under the influence of centrifugal force resulting from rotation of the device.

United States Patent Mainhardt et a1.

[ ROTATABLE ROCKET HAVING MEANS FOR PREVENTING FLAMEOUT DUE TOCENTRIFUGAL FORCE CREATED DURING ROTATION THEREOF 51March 13, 19732,773,448 12/1956 Jasse ..l02/49.7 X

, 2,785,632 3/1957 Clauser et a1 ..l02/35.6 X 3,038,407 6/1962 Robertsonet a1. ..lO2/49.5 X

Primary ExaminerVer1in R. Pendegrass Att0rney-Harness, Dickey & Pierce[76] Inventors: Robert Mainhardt, P.O. Box 225,

Diablo, Calif. 94528; David L. t Cochran, 165 Valle Verde, Dan- [57]ABSTRACT Ville, Calif- 94526; Arthur A rocket device comprising anelongated generally tu- Q Y, 5171 oakvlfiw Court, bular shaped housing;a propulsion charge in one end Calif- 94566; of the housing; means fordirecting the products of Frltzler, 1100 Lincoln, Apt- 35, combustion ofthe propulsion charge rearwardly of the Walnut Crack; Calif- 94546;Robe" housing in a manner so as to impart rotary motion to C. Mawhinney,170 Camino Encanthe device as it is propelled forwardly by the charge;to, Danville, Calif. 94526 signal means in the form of a quantity ofradar signal- Filed: p 16 1970 mg chaff in the housing; an expulsioncharge for expelling the signaling means from the housing; means [21]App]. No.: 28,219 including a combustable material within the housingfor igniting the expulsion charge: at a predetermined Related PP Dantime after the propulsion charge has been ignited, and' [63]Continuation-impart of Ser, No. 694,208, Dec. 28, an Closure forOperatively Supporting the wmbusta- 1967, abandonc ble material withinthe housing and for preventing the ignited portion .of the combustablematerial from 52 0.5. CI. ..1o2/34.4, 102/34.3, 102/493 being forced outof the enclosure under the influence [51] Int. Cl ..F42b 13/40 ofcentrifugal force resulting fmm of the [58] Field of Search....l02/34.3, 34.4, 35.6, 37.6, devlce- [56] References Cited 4 Claims,3 Drawing Figures UNITED STATES PATENTS 2,442,528 6/1948 Beattie....102/34.3 X

/d a 3 1 J4 I j; //////1/// #11411 I z 14 filwa ii t/ w 1/ v 2 iW/ 4- I"A Q 2 a ;Z- 35d 1Z4 s &- 4 i T r T- W n /4 f// )8 I l I 71/] \t 1L Z/1/ l I! w 44 f4 4/ 4 4 0 J BACKGROUND OF THE INVENTION Extensiveresearch into rocket type projectiles has indicated that gyroscopicstabilization thereof maximizes the control and efficiency of flighttrajectory.

Accordingly, such gyroscopic stabilization techniques have beenincorporated in a variety of different types of rocket-like devices,including rocket devices of the type used for personnel rescueandsimilar type signaling purposes. By way of example, common types ofrescue rockets incorporate pyrotechnic or combustable illuminatablesubstancesor, alternatively, various types of radar sensing chaff,thepresence of which may-be noted by various types of electronic searchingand scanning devices such as radaror the like.

It is the common practice in such rescue rockets to provide a propulsioncharge adapted to propel the rocket to a predetermined altitude and anexpulsion chargewhich functions to expel a particular signalingapparatus, such as the aforementioned pyrotechnic or chaff type devices,away from the rocket a predetermined time after the propulsion chargehas been ignited. In order to provide for a delayed ignition of theexpulsion charge, a delay train or timing fuse is usually providedin-such signaling or rescuerockets. Com-' monly, the delay train is inthe form-of a charge of a combustable material which turns to asemi-liquid state upon ignition thereof and is adapted to burn at apredetermined rate preparatory to effecting ignition of the associatedexpulsion charge.

Although the aforementioned delay trains or timing fuses have functionedsatisfactorily in conventional rockets, such devices for delaying theignition of the expulsion charges in rescue type rockets have beenobjectionable when such rocket devices have incorporated means forproviding for gyroscopic stabilization thereof. The reason for this isthat once such gyroscopi cally stabilized rockets have been launched,they rotate at a predetermined speed as they are propelled along theirflight path inorder to effectuate stable flight; however, it has beenfound that such rotative movement of the rocket creates a centrifugalforce upon the combustable material of the delay train of sufficientmagnitude to force or throw the ignited material out of its respectiveenclosure withinthe rocket, with the result that the delay train sufferswhat is commonly known as a flame-out" or a cessation of ignition. Ofcourse, when the delay train experiences such a malady, the associatedexpulsion charge is not ignited at the predetermined time and thesignaling device incorporated in the rocket is not expelled and is thusrendered inoperative.

In accordance with the principles of the present invention, theaforementioned objectionable characteristics heretofore experienced ingyroscopically stabilized rescue rockets is virtually entirely overcomethrough the provision of a novel rocket device incorporating a delaytrain or timing fuse having means adapted to prevent the combustablematerial disposed sure, with the result that possible flame-outconditions are effectively and positively prevented.

SUMMARY OF THE INVENTION This invention relates generally to rocket-likedevices and, more particularly, to a rocket propelled device forprojecting a radar signaling material to an altitude such that saidmaterial may be detected by radar or the like.

It is accordingly a generally object of the present invention to providea new and improved radar signaling rocket.

It is a more particular object of the present invention to provide a newand improved rocket device for projecting radar signaling chaff to analtitude where such material may be detected as by radar.

It is still a more particular object of the present invention to providea new and improved radar signaling rocket of the type which rotates asit is projected forwardly, and which includes means for preventing thecombustable material comprising the delay train thereof from beingforced from its associated enclosure means within the rocket housingunder the influence of centrifugal force resulting from rotation of therocket.

It is another object of the present invention to provide a new andimproved device of the above character which includes a generallyrestricted or reduced diameter discharge opening in the enclosure meansfor the combustable material of the delay train, the discharge openingbeing defined by a generally inwardly extending wall portion thatprevents any of the ignited combustable material for being forced out ofthe lower end of the delay train enclosure.

It is yet another object of the present invention to provide a new andimproved radar signaling rocket of the above character which is of asimple design, is easy to assemble and economical to commerciallymanufacture.

Other objects and advantages of the present invention will becomeapparent from the following detailed description taken in conjunctionwith the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a longitudinal crosssectional view of a radar signaling rocket in accordance with apreferred construction of the present invention;

FIG. 2 is an end elevational view of the rocket illustrated in FIG. 1,as seen in the direction of the arrow 1 DESCRIPTION OF A PREFERREDEMBODIMENT For purposes of description, the terms forwardly" andrearwardlyl will have reference to the rescue rocket of the presentinvention as shown in FIGS. 1 and 3 of the drawing, with the forward endof the rocket being located at the right side of these figures and therearward end being located at the left side of said figures. Also, theterms inwardly", outwardly" and derivatives thereof will have referenceto the geometric center of the rocket device of the present inventionand the various component parts thereof.

It will be noted that the principle of the present invention will findparticularly useful application when incorporated in rocket-like devicesof the type used for personnel rescue purposes. Accordingly and by wayof example, the present invention is illustrated herein in operativeassociation with a radar type rescue rocket. It-

will be readily apparent, of course, that the scope of the presentinvention is' not intended to be limited to the illustrative embodimentshown and described herein since wide and varied alternativeapplications will be obvious to any person skilled in the rocketry art.

Referring now in detail to the drawing, a signal or rescue rocket,generally designated by the numeral 10,

is shown as comprising an elongated cylindrical casing or housing 12that is substantially closed at the rearward end thereof by a generallytransversely extending nozzle plate 14. The plate 14 is formed with anannular recess 16 around the outer periphery thereof and is adapted tobe fixedly secured within the rearward end of the housing 12 by having aportion of the housing 12 swaged or deformed radially inwardlyinto'engagement with the periphery of the recess portion 16, as seen at18 in FIG. 1. The nozzle plate 14 is formed with a plu-. rality ofdischarge orifices 20 equally circumferentially and radially spacedtherearound, as best seen in FIG. 2. The orifices 20 are communicable attheir forward ends with the interior of the housing 12 and arecommunicable at their rearward ends with generally rearwardly taperedenlarged diameter wall portions, generally designated 22. As illustratedin FIG. 2, the tapered wall portions 22 are canted or inclined in thesame circumferential direction, i.e. counterclockwise, for reasons laterto be described in effecting rotational stabilizing movement of therocket 10 as it is propelled forwardly.

The nozzle plate 14 is provided with a centrally located primer orsimilar type ignition device which is fixedly mounted within a suitableprimer seat or opening 26 formed in the plate 14. Extending across theinterior or forwardmost side of the nozzle plate 14 is relatively thin,preferably rupturable, diaphragm member 28 that is fabricated of arelatively thin sheet of aluminum which may, for example, be secured tothe forward side of the nozzle plate 14 by a suitable pressure or heatsensitive adhesive. The diaphragm 28 functions both as a hermetic sealfor the lower end of the rocket 10, and to facilitate pressure buildupinternally of the housing 12 upon firing of the primer 24.

Disposed within the rearward end of the housing 12 immediately forwardlyof the diaphragm 28 is a quantity of propellant which may be of anysuitable type known in the art. The propellant is in the form of agenerally cylindrical charge 30 having generally frustoconical recessedportions 31 formed at the forward and rearward ends thereof, therecessed portions 31 being connected by means of an axially disposedcentral passage 32 which extends the entire length of the charge 30.Preferably, the outer diameter of the cylindrical charge 30 issubstantially the same size as the inner diameter of the housing 12whereby to preclude any relative movement therebetween upon assembly ofthe rocket 10.

Referring now to the forward end of the housing 12 and to the signalingor rescue device incorporated in the rocket 10, there is provided agenerally elongated cylindrical or tubular casing 34, the outer diameterof which is adapted to be slightly smaller in size than the innerdiameter of the housing 12, whereby the casing 34 may be nestinglyreceived within the forward end of the housing 12, as illustrated inFIG. 1. The forward end of the casing 34 is closed by a transverselyextending partition member or end plug 36 which may be press fittedwithin the forward end of the housing 12, as shown in FIG. 1. Therearward end of the casing 34 is closed by another transverselyextending partition member 38 which is also press fitted within theinterior of the housing 12 and is preferably fabricated of a feltlikematerial. The partition member 38 is designed to protect the contents ofthe casing 34 from the products of combustion of the expulsion chargeused to expel the casing 34 from within the housing 12, as will later bedescribed. In the embodiment of the present invention illustratedherein, the interior of the casing 34 is provided with a series ofadjacent chaff charges, generally designated 40, which are composed ofany suitable chaff material of the type capable of being sensed on asuitable radar scanning apparatus or the like. By way of example, thechaff charges 40 may be composed of metallicparticles such as wire gneshmetallic shavings or the like. It will be apparent, of course, that thecasing 34 may be provided with some type of signaling apparatus otherthan the chaff 40 as, for example, an illuminating signal device or thelike.

Disposed directly rearwardly of the felt partition member 38 is atransversely extending piston that is preferably fabricated of aluminumand is adapted to be slidably disposed within the interior of thehousing 12 in the manner as illustrated in FIG. 1. As will hereinafterbe described, the piston 42 is adapted to move longitudinally of thehousing 12 toward the forward end of the rocket 10 upon ignition of theexpul' sion charge in the rocket 10, thus effecting removal of thecasing 34 and the chaff 40 from within the housing 12.

As best seen in FIG. 1, an annular spacer member, generally designated44, is disposed within the housing 12 directly rearwardly of the pistonmember 42. The spacer member 44 comprises an'annular or cylindricalsection 46 that is adapted to be fixedly secured within the interior ofthe housing 12, as illustrated. The member 44 also comprises atransversely extending partition section 48 that projects radiallyinwardly from the interior of the section .46 and defines a centralannular bore 49. The sections 46 and 48 of the member 44, together withthe rearward side of the piston 42 define an annular cavity 50 which isfilled with an expulsion charge, generally designated by the numeral52.,The charge 52 may be composed of any suitable explosive materialsuch as black powder or a similar material having sufficient explosivepower to expel the casing 34 and chaff charges 40 contained therein fromwithin the interior of the housing 12.

In order to effect ignition of the expulsion charge 52 at apredetermined time after the ignition of the propellant 30, the rocketis provided with a delay train or timing fuse arrangement interjacentforward end of the propellant 30 and the rearward end of the expulsioncharge 52. In particular, the delay train comprises an enclosure member,generally designated by the numeral 54, which comprises a transverselyextending bulkhead section 56 having an annular, radially inwardlyextending recess portion 58 formed therein. The member 54 is preferablyfabricated of aluminum or a similar light weight material and is adaptedto be fixedly secured within the housing 12 by having a central portionof the housing 12 swaged on similarly deformed radially inwardly intothe recess portion 58, as seen at 60 in FIGS. 1 and 3. The member 54comprises an integral centrally located cylindrical or tubular enclosuresection 62 that projects forwardly from the forward side of the bulkheadsection 56, as shown in FIG. 1, the enclosure section 62 extendingforwardly through the central opening 49 and terminating at its forwardend directly adjacent the expulsion charge 52 within the cavity 50. Theenclosure section 62 and the forwardmost portion of the bulkhead section56 define a generally cylindrical cavity 64 adapted to contain acombustable delay element or timing fuse 66 which may be of any suitablematerial adapted to burn at a preselected rate, whereby to function inigniting the expulsion charge 52 at a preselected time after ignition ofthe propellant 30, as will later be described.

In accordance with the principles of the present invention, the member54 is provided with means adapted to prevent the combustable material 66comprising the timing fuse and which transforms to a semiliquid state asit burns toward the expulsion charge 52 from being thrown or forced outof the rearward end of the cavity 64 under the influence of centrifugalforce due to rotation of the rocket 10 during its forward propulsion.Such means is provided by a generally radially inwardly extending wallportion or shoulder 68 integrally formed on the member 54 and extendinginwardly from the rearward end of the cavity 64. As best illustrated inFIG. 3, the wall portion 68 defines a centrally located restricteddischarge orifice 70 and is defined by a rearwardly and inwardlyinclined surface or face 72 and a generally radially extending face 74which is preferably coplanar with the rearward side of the bulkheadsection 56, as shown. In a preferred construction of the presentinvention, the wall portion 68 encloses approximately one-half of therearward end of the cavity 64, with the result that the diameter of therestricted orifice 70 is approximately one-half the diameter of thecavity 64. It may be noted that the relative size of the wall portion 68with respect to the diameter of the cavity 64 may be varied inaccordance the type ofmaterial 66 comprising the delay train, as well aswith the configuration of the enclosure section 62 and size of therocket 10.

From the above description, it will be seen that upon ignition of thecombustable material 66 of the delay train, the wall portion 68 willprevent the rearwardmost part of this material from being forcedoutwardly through the discharge orifice as the rocket 10 rotates orspins while it is projected forwardly. Accordingly, the combustablematerial 66, upon being initially ignited, will burn smoothly andcontinuously for a predetermined amount of time prior to effectingignition of the expulsion charge 52, with the possibility of a flame-outof the material 66 being positively prevented.

In operation of the rescue rocket 10 of the present invention, therocket 10 is adapted to be fired as, for example, from a rnortar'orsimilar type apparatus having fixed firing pin. When it is desired tofire the rocket 10, the same is dropped into the mortar with therearward end thereof facing downward, with the result that when therocket 10 strikes the firing pin located at the lower end of theinterior of the mortar, the primer 24 will be exploded. Upo'n explosionof the primer 24, the diaphragm 28 is ruptured and the propulsion charge30 is ignited, and at the same time the combustable material 66 in thedelay train is ignited. The products of combustion of the propellant 30vent through the discharge orifices 20 in the nozzle plate 14, drivingthe rocket 10 from the mortar and to a predetermined altitudeQTheangular disposition of the walls 22 adjacent each of the dischargeorifices 20 causes the rocket 10 to spin orrotate about its longitudinalaxis, whereby to achieve gyroscopic stabilization of the rocket 10. Uponignition of the material 66 of the delay train, said material will beginto burn from the rearward end thereof toward the forward end, with suchmaterial being transformed into a liquid or semi-liquid state due to theheat of combustion thereof. As above described, the radially extendingwall portion 68 prevents the liquid portion of the combustable material66 from being forced out of the rearward end of the cavity 64 as therocket is rotating, thus assuring continuous ignition of the material66. When the rocket has been propelled to a predetermined altitude, thecombustable material 66 will be completely burned out and will ignitethe expulsion charge 52 disposed within the cavity 50. Ignition of thecharge 52 results in explosion thereof, which in turn results in thepiston member 42 forcing the easing 34 longitudinally outwardly(forwardly) from the forward end of the housing 12. As the casing 34 isforced out of the housing 12, the chaff charges 40 will be expelled intothe atmosphere, which charges 40 will thereafter fall to the earth withtheir presence being indicated and their location being identified on aradar screen or similar type scanning and identification equipment.

We claim:

1. In a rocket device,

:an elongated generally tubular shaped housing,

a propulsion charge in one end of said housing,

means for directing the products of combustion of said charge rearwardlyof said housing in a manner so as to impart rotary motion to said deviceas it is propelled forwardly by said charge,

signal means in said housing,

an expulsion charge for expelling said signal means from said housing,

a time delay fuse comprising a combustable material for igniting saidexpulsion charge at a predetermined time after said propulsion chargehas been ignited, said fuse normally being in a solid state and beingtransformable from said solid state to a semi-liquid state uponcombustion thereof, and

enclosure means for operatively supporting said time delay fuse withinsaid housing, said enclosure means comprising a generally cylindricallyshaped cavity located substantially coaxially of the device andterminating at one end thereof in a radially inwardly extending portionfor preventing the semiliquid ignited portion of said combustablematerial from being forced out of said enclosure means under theinfluence of centrifugal force resulting from the rotation of saiddevice sufficiently to prevent cessation of ignition of said time delayfuse, said radially inwardly extending portion defining a relativelyrestricted discharge orifice through which the products of combustion ofsaid combustable material are expelled, said orifice being locatedsubstantially coaxially of the axis of rotation of said housing.

2. A rocket device as set forth in claim 1 which includes a generallycylindrical shaped enclosure member for supporting said combustablematerial within said housing, said member including means defining adischarge opening and an inwardly extending wall portion arrangedcireumjacent said opening and adapted to prevent said combustablematerial from being forced out of enclosure member upon rotation of saiddevice.

3. A rocket device as set forth in claim 1 wherein said means forimparting rotary motion to said device comprising a plurality of canteddischarge openings provided in the lower end of said housing, whereinsaid enclosure means comprises a generally cylindrical shaped enclosurecommunicable at one end with said expulsion charge, the opposite end ofsaid enclosure including a generally restricted discharge openinglocated substantially coaxially of the axis of rotation of said housingdefined by an inwardly extending wall adapted to prevent the combustablematerial within said enclosure from being forced outwardly therefromupon rota tion of said device.

4. A rocket device as set forth in claim 2 wherein said inwardlyextending wall portion encloses approximately one half of the lower endof said cavity.

# i l i

1. In a rocket device, an elongated generally tubular shaped housing, apropulsion charge in one end of said housing, means for directing theproducts of combustion of said charge rearwardly of said housing in amanner so as to impart rotary motion to said device as it is propelledforwardly by said charge, signal means in said housing, an expulsioncharge for expelling said signal means from said housing, a time delayfuse comprising a combustable material for igniting said expulsioncharge at a predetermined time after said propulsion charge has beenignited, said fuse normally being in a solid state and beingtransformable from said solid state to a semi-liquid state uponcombustion thereof, and enclosure means for operatively supporting saidtime delay fuse within said housing, said enclosure means comprising agenerally cylindrically shaped cavity located substantially coaxially ofthe device and terminating at one end thereof in a radially inwardlyextending portion for preventing the semi-liquid ignited portion of saidcombustable material from being forced out of said enclosure means underthe influence of centrifugal force resulting from the rotation of saiddevice sufficiently to prevent cessation of ignition of said time delayfuse, said radially inwardly extending portion defining a relativelyrestricted discharge orifice through which the products of combustion ofsaid combustable material are expelled, said orifice being locatedsubstantially coaxially of the axis of rotation of said housing.
 1. In arocket device, an elongated generally tubular shaped housing, apropulsion charge in one end of said housing, means for directing theproducts of combustion of said charge rearwardly of said housing in amanner so as to impart rotary motion to said device as it is propelledforwardly by said charge, signal means in said housing, an expulsioncharge for expelling said signal means from said housing, a time delayfuse comprising a combustable material for igniting said expulsioncharge at a predetermined time after said propulsion charge has beenignited, said fuse normally being in a solid state and beingtransformable from said solid state to a semi-liquid state uponcombustion thereof, and enclosure means for operatively supporting saidtime delay fuse within said housing, said enclosure means comprising agenerally cylindrically shaped cavity located substantially coaxially ofthe device and terminating at one end thereof in a radially inwardlyextending portion for preventing the semiliquid ignited portion of saidcombustable material from being forced out of said enclosure means underthe influence of centrifugal force resulting from the rotation of saiddevice sufficiently to prevent cessation of ignition of said time delayfuse, said radially inwardly extending portion defining a relativelyrestricted discharge orifice through which the products of combustion ofsaid combustable material are expelled, said orifice being locatedsubstantially coaxially of the axis of rotation of said housing.
 2. Arocket device as set forth in claim 1 which includes a generallycylindrical shaped enclosure member for supporting said combustablematerial within said housing, said member including means defining adischarge opening and an inwardly extending wall portion arrangedcircumjacent said opening and adapted to prevent said combustablematerial from being forced out of enclosure member upon rotation of saiddevice.
 3. A rocket device as set forth in claim 1 wherein said meansfor imparting rotary motion to said device comprising a plurality ofcanted discharge openings provided in the lower end of said housing,wherein said enclosure means comprises a generally cylindrical shapedenclosure communicable at one end with said expulsion charge, theopposite end of said enclosure including a generally restricteddischarge opening located substantially coaxially of the axis ofrotation of said housing defined by an inwardly extending wall adaptedto prevent the combustable material within said enclosure from beingforced outwardly therefrom upon rotation of said device.